MIGRATE_HOTREMOVE is a special kind of MIGRATE_MOVABLE, but it is stable:
any page of the type can NOT be changed to the other type nor be moved to
the other free list.
So the pages of MIGRATE_HOTREMOVE are always movable, this ability is
useful for hugepages and hotremove ...etc.
MIGRATE_HOTREMOVE pages is the used as the first candidate when
we allocate movable pages.
1) add small routine is_migrate_movable() for movable-like types
2) add small routine is_migrate_stable() for stable types
3) fix some comments
4) fix get_any_page(). The get_any_page() may change
MIGRATE_CMA/HOTREMOVE types page to MOVABLE which may cause this page
to be changed to UNMOVABLE.
Signed-off-by: Lai Jiangshan <laijs@xxxxxxxxxxxxxx>
---
include/linux/mmzone.h | 34 ++++++++++++++++++++++++++++++++++
include/linux/page-isolation.h | 2 +-
mm/compaction.c | 6 +++---
mm/memory-failure.c | 8 +++++++-
mm/page_alloc.c | 21 +++++++++++++--------
mm/vmstat.c | 3 +++
6 files changed, 61 insertions(+), 13 deletions(-)
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 979c333..872f430 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -58,6 +58,15 @@ enum {
*/
MIGRATE_CMA,
#endif
+#ifdef CONFIG_MEMORY_HOTREMOVE
+ /*
+ * MIGRATE_HOTREMOVE migration type is designed to mimic the way
+ * ZONE_MOVABLE works. Only movable pages can be allocated
+ * from MIGRATE_HOTREMOVE pageblocks and page allocator never
+ * implicitly change migration type of MIGRATE_HOTREMOVE pageblock.
+ */
+ MIGRATE_HOTREMOVE,
+#endif
MIGRATE_ISOLATE, /* can't allocate from here */
MIGRATE_TYPES
};
@@ -70,6 +79,31 @@ enum {
# define cma_wmark_pages(zone) 0
#endif
+#ifdef CONFIG_MEMORY_HOTREMOVE
+#define is_migrate_hotremove(migratetype) ((migratetype) == MIGRATE_HOTREMOVE)
+#else
+#define is_migrate_hotremove(migratetype) false
+#endif
+
+/* Is it one of the movable types */
+static inline bool is_migrate_movable(int migratetype)
+{
+ return is_migrate_hotremove(migratetype) ||
+ migratetype == MIGRATE_MOVABLE ||
+ is_migrate_cma(migratetype);
+}
+
+/*
+ * Stable types: any page of the type can NOT be changed to
+ * the other type nor be moved to the other free list.
+ */
+static inline bool is_migrate_stable(int migratetype)
+{
+ return is_migrate_hotremove(migratetype) ||
+ is_migrate_cma(migratetype) ||
+ migratetype == MIGRATE_RESERVE;
+}
+
#define for_each_migratetype_order(order, type) \
for (order = 0; order < MAX_ORDER; order++) \
for (type = 0; type < MIGRATE_TYPES; type++)
diff --git a/include/linux/page-isolation.h b/include/linux/page-isolation.h
index 3bdcab3..b1d6d92 100644
--- a/include/linux/page-isolation.h
+++ b/include/linux/page-isolation.h
@@ -15,7 +15,7 @@ start_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn,
unsigned migratetype);
/*
- * Changes MIGRATE_ISOLATE to MIGRATE_MOVABLE.
+ * Changes MIGRATE_ISOLATE to migratetype.
* target range is [start_pfn, end_pfn)
*/
extern int
diff --git a/mm/compaction.c b/mm/compaction.c
index 7ea259d..e8da894 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -47,7 +47,7 @@ static void map_pages(struct list_head *list)
static inline bool migrate_async_suitable(int migratetype)
{
- return is_migrate_cma(migratetype) || migratetype == MIGRATE_MOVABLE;
+ return is_migrate_movable(migratetype);
}
/*
@@ -375,8 +375,8 @@ static bool suitable_migration_target(struct page *page)
if (PageBuddy(page) && page_order(page) >= pageblock_order)
return true;
- /* If the block is MIGRATE_MOVABLE or MIGRATE_CMA, allow migration */
- if (migrate_async_suitable(migratetype))
+ /* If the block is movable, allow migration */
+ if (is_migrate_movable(migratetype))
return true;
/* Otherwise skip the block */
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index ab1e714..f5e300d 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1367,6 +1367,7 @@ static struct page *new_page(struct page *p, unsigned long private, int **x)
static int get_any_page(struct page *p, unsigned long pfn, int flags)
{
int ret;
+ int mt;
if (flags & MF_COUNT_INCREASED)
return 1;
@@ -1377,6 +1378,11 @@ static int get_any_page(struct page *p, unsigned long pfn, int flags)
*/
lock_memory_hotplug();
+ /* Don't move page of stable type to MIGRATE_MOVABLE */
+ mt = get_pageblock_migratetype(p);
+ if (!is_migrate_stable(mt))
+ mt = MIGRATE_MOVABLE;
+
/*
* Isolate the page, so that it doesn't get reallocated if it
* was free.
@@ -1404,7 +1410,7 @@ static int get_any_page(struct page *p, unsigned long pfn, int flags)
/* Not a free page */
ret = 1;
}
- unset_migratetype_isolate(p, MIGRATE_MOVABLE);
+ unset_migratetype_isolate(p, mt);
unlock_memory_hotplug();
return ret;
}
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index efc327f..7a4a03b 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -667,7 +667,7 @@ static void free_pcppages_bulk(struct zone *zone, int count,
page = list_entry(list->prev, struct page, lru);
/* must delete as __free_one_page list manipulates */
list_del(&page->lru);
- /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
+ /* MIGRATE_MOVABLE list may include other types */
__free_one_page(page, zone, 0, page_private(page));
trace_mm_page_pcpu_drain(page, 0, page_private(page));
} while (--to_free && --batch_free && !list_empty(list));
@@ -1058,6 +1058,14 @@ static struct page *__rmqueue(struct zone *zone, unsigned int order,
{
struct page *page;
+#ifdef CONFIG_MEMORY_HOTREMOVE
+ if (migratetype == MIGRATE_MOVABLE) {
+ page = __rmqueue_smallest(zone, order, MIGRATE_HOTREMOVE);
+ if (likely(page))
+ goto done;
+ }
+#endif
+
page = __rmqueue_smallest(zone, order, migratetype);
#ifdef CONFIG_CMA
@@ -1071,6 +1079,7 @@ static struct page *__rmqueue(struct zone *zone, unsigned int order,
if (unlikely(!page))
page = __rmqueue_smallest(zone, order, MIGRATE_RESERVE);
+done:
trace_mm_page_alloc_zone_locked(page, order, migratetype);
return page;
}
@@ -1105,11 +1114,7 @@ static int rmqueue_bulk(struct zone *zone, unsigned int order,
list_add(&page->lru, list);
else
list_add_tail(&page->lru, list);
- if (IS_ENABLED(CONFIG_CMA)) {
- mt = get_pageblock_migratetype(page);
- if (!is_migrate_cma(mt) && mt != MIGRATE_ISOLATE)
- mt = migratetype;
- }
+ mt = get_pageblock_migratetype(page);
set_page_private(page, mt);
list = &page->lru;
}
@@ -1392,7 +1397,7 @@ int split_free_page(struct page *page)
struct page *endpage = page + (1 << order) - 1;
for (; page < endpage; page += pageblock_nr_pages) {
int mt = get_pageblock_migratetype(page);
- if (mt != MIGRATE_ISOLATE && !is_migrate_cma(mt))
+ if (mt != MIGRATE_ISOLATE && !is_migrate_stable(mt))
set_pageblock_migratetype(page,
MIGRATE_MOVABLE);
}
@@ -5465,7 +5470,7 @@ __count_immobile_pages(struct zone *zone, struct page *page, int count)
if (zone_idx(zone) == ZONE_MOVABLE)
return true;
mt = get_pageblock_migratetype(page);
- if (mt == MIGRATE_MOVABLE || is_migrate_cma(mt))
+ if (is_migrate_movable(mt))
return true;
pfn = page_to_pfn(page);
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 1bbbbd9..44a3b7f 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -616,6 +616,9 @@ static char * const migratetype_names[MIGRATE_TYPES] = {
#ifdef CONFIG_CMA
"CMA",
#endif
+#ifdef CONFIG_MEMORY_HOTREMOVE
+ "Hotremove",
+#endif
"Isolate",
};
--
1.7.4.4
--
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